Optical device for distant vision



March 31,1931. G. VALENSI 1,798,963

OPTICAL DEVICE FOR DISTANT VISION Filed July 15, 1927 Patented Mar. 31,1931 UNITED STATES GEORGES VALENSI,

PATENT OFFICE OF PARIS, FRANCE OPTICAL DEVICE FOR DISTAN'I. VISIONApplication filed July 15, 1927, Serial No.

* provided with transparent lines (or slots 01' perforations). Thesediscs are adapted to rotate at a high speed and in such a way that thepoint where said transparent lines or perforations register moves alongthe whole surface of the object or of the drawing to be seen at distance(in the case of the transmission) or of the image to be reconstituted(in the case of the reception).

Referring to the drawings in which like parts are similarly designatedFigure 1 illustrates one of the scanning discs provided with arcuateslots.

Fig. 2 is a similar view showing the relation of two images to the slotsof the discs. gig. 3 illustrates a manner of illumination,

Fig. 4. a manner of intensive illumination of an object.

Figure 1 shows an exampleof such scan ning disc provided with a slotmade of spiral arcs whose equation in polar coordinates re lated to thecenter of said discis linear. If two discs of this kind rotate aroundthe same different speeds, each square, such as the one represented bydotted lines on Fig. 1 corresponds to an image, said imagebeing exploredin this case in a continuous manner and at a uniform speed. The samediscs permit consequently to explore at the same time several images. sothat they may be used simultaneouslyfor transmission and for reception,and also for television or telephotography of colors (with the threecolor process) and of relief (with the stereoscopic process) withoutincreasing in any way the difficulties of synchronization between the206,064, and. in France December a, 1926.

corresponding to the portion 19 (at the right of Fig. 2) is scannedpoint by point, and afterwards the part of the second imagecorresponding to the portion 19"a (at the left of Fig. 2) is scannedpoint by point. If, by means of suitable optical devices as describedhereinafter, the two portions of images corresponding to 19 and 19"a arejuxtaposed (the other portions of the two squares of Fig.

2 which are not covered with lines being conveniently masked), it isclear that the scanning process will take place as if only one and the.same image was scanned point by point in a continuous manner and at auni-' form speed, although distinct and complementary portions 19" and19"a of the circumference of the scanning disc are used one after theother for said scanning process.

As it is well known in the television art, such scanning discs might beused in a sending television apparatus for illuminating point by pointthe object to be seen at a distance, the light emitted by the variouspoints of said object successively illuminated acting on a photoelectriccell which translates into electrical variations the variations inlightand shade of saidvarious points of said object. axis in oppositedirections and with slightly One way of performing such an illuminationof the object to be seen at a distance is represented on Fig. 3.

The fixed, or moving, object 31 to be trans mitted is placed in a darkchamber (not shown on the drawing) and its various points aresuccessively illuminated. This result is obtained by means of an intensesource of light 19 (for instance the incandescent end of the coal stickof a Garbarini electric are, or the filament of a powerful incandescentlamp of the projector type) associated with a dioptric systemconstituted, for example, by the lenses 33 and 34. This dioptric systemproduces a luminous cone of small angle in which are inserted, at anysuitable point, the scanning discs 1 and 2 and the object to betransmitted, 31. Because of the relative motion and the shape of thetransparent lines of said scanning discs, a luminous point of constantbrilliancy will explore the whole surface of the object 31 in acontinuous man- CPL nor and at a uniform speed if discs 1 and 2 are thesame as shown in Figure 1.

In order to utilize all the luminous rays emitted by the incandescentpoint 19 (which are distributed over an angle of 180 degrees) use ismade of the aplanetic spherical lens 34; the concave surface of saidlens is a hemisphere of center 19 and consequently all the rays emittedby 19 are taken by said lens and give after refraction an image 19 of 19so located that the emergent luminous cone has only a small angle.

This luminous cone of small angle produced by lens 3 1 would givethrough the lens (or through a suitable dioptric system) 33 an image 19"of point 19 if a mirror (or a prism or other suitable optical device)did not deviate the luminous rays to make them converge at point19. v r

The object 31 to be transmitted is placed in the path of the raysconverging in 19" and the scanning discs 1 and 2 are placed at asuitable point between the lens 33 and the object 31. Consequently thevarious points of said object are illuminated successively. The image 31of said object 31 through the lens (or photographic objective or opticaldevice of suitable kind) 41 is formed inside a diaphragm on the windowof the photoelectric cell 42.

The relative positions of mirror 40, discs 1 and 2 and object 31 maydiffer from those shown in Fig. 3. Mirror 40* could be placed after 19"onthe opposite part of the luminous cone converging at 19".

Also if the source of light 19 has a uniform brilliancyon its wholesurface it is convenient to form its image 19" exactly between discs 1and 2 and in order to increase the illumination of the object 31.

The object of the present invention is an illuminating sending scanningdevice in which, in order to increase as much as possible theillumination of the variouspoints of the object successively, use ismade of a plurality of sources of light at the same time, so locatedthat their respective pencils of light fall on distinct andcomplementary portions of the circumference of discs 1 and 2; theluminous pencils produced by these different sources of light beingjuxtaposed exactly on the surface of object 31, which will beconsequently highly illuminated. I

For example, two sources of light 19, 19a are used simultaneously in adevice according to this invention, and shown in Fig. 1, which is builtup byuxtaposing two structures similar to Fig. 3. The lenses 34: and 33give from source 19 an imagelocated in 19 between discs 1 and 2 andsupposed to cover exactly the rectangle represented in 19"a on Figure 2.

The optical means 40 embodying as reflecting surfaces mirrors or thes1des of a prism give an lmage of the rectangle 19a exactly on the righthalf of object 31; Similarly the lenses from said object.

2. Illumination sending scanning device, comprising 1n combination,separate sources 34a and 33a; given an image 19a of source 19a locatedbetween discs 1 and 2 and supposed to cover exactly the rectanglerepresented in 19"a on Fig. 2. The optical means 40a builds an image ofthe rectan le 19"a exactly on the left half of object 31. 11 front of,and very close to object 31 is placed the photoelectric cell 42 (forexample associated with a lens 41 giving an image of object 31 on thewindow of said cell 42).

The advantages of the illumination sending scanning device according tothis invention are'first, to concentrate .a greater amount, of lightsuccessively on the various points of the scanned object; because thepencils of powerful sources of light arejuxtaposed on said objectthrough distinct-and complementary portions of the circumference of thesame scanning discs; and, second,

the placing of the photoelectric cell in front of said object, and asclose as possible, in

order to collect in said cell the greatest possible amount of the lightreflected by said object.

I claim 2- 1. Illumination sending scanning device for televisioncomprising exploring means, a. plurality of sources of light arranged toilluminate distinct complementary portions of said exploring means, aplurality of optical means to cause the beams passing one after theother through said exploring means to sweep one after the other separateportions of the object to be seen at distance, the whole surface of'said object being swept by said beams in complementary areassuccessively, and a photoelectric cell mounted in front of said objectand receiving reflected beams of light, exploring'means associated witheach source, optical means, for each source focussing the beams onjuxtaposed areas of the object to be seenat distance, said exploringmeans sinuously exploring the respe'ctivejuxtaposed areas in succession,and photo-electric cells mounted in front of said object and re-.

'ceiving reflected beams from said object.

3. Illumination sending scanning device for television in accordancewith claim 1, comprising scanning discs, a plurality .of sources oflight each having a small surface of great and uniform brightness, aplurality of spherical lenses having, concave surfaces in form ofhemispheres said sources being located at the centers of saidhemispheres, a plurality of optical means embodying reflecting surfaces,a photoelectric cell, said optical means focussing the luminous cones ofsmall angle produced by said spherical lenses exactly on distinctcomplementary portions of said scanning discs, and further juxtaposingthe luminous pencils on theobject to be seen at distance, said objectbeing placed in front of said photoelectric cell.

4:. A point by point sending device, comprising exploring means, aplurality of sources of light arranged to illuminate distinctcomplementary portions of said exploring means, a plurality of opticalmeans to cause the beams from the exploring means to sweep one after theother separate portions of the object, the whole surface of the objectbeing swept by said beams, and a photoelectrio cell mounted in front ofthe object and receiving reflected beams from the object.

5. A point by point sending device, comprising exploring means, aplurality of sources of light to successively explore through said meansdifferent portions of an object, a plurality of optical means includingreflecting surfaces through which the light passes to the object, theWhole surface of the object being swept by each beam in complementaryareas, and a photelectric cell disposed in front of the object and actedupon by the beams reflected therefrom.

6. In a distant vision installation, the combination with separatesources of light; of exploring means associated with each source,optical systems for each source focussing the beams on juxtaposed areasof the object, said exploring means sinuously exploring the respectivejuxtaposed areas in succession.

In testimony that I claim the foregoing as my invention, I have signedmy name.

GEORGES VALENSI.

